Field
Aspects of the present invention generally relate to a cartridge that includes an electrophotographic photosensitive drum for use in an electrophotographic image forming apparatus.
Description of the Related Art
In an electrophotographic image forming apparatus (hereinafter, also referred to as an “image forming apparatus”), typically, a drum-shaped electrophotographic photosensitive drum serving as an image bearing member is uniformly charged. The charged electrophotographic photosensitive drum is then selectively exposed to form an electrostatic latent image (electrostatic image) on the electrophotographic photosensitive drum. The electrostatic latent image formed on the electrophotographic photosensitive drum is developed as a toner image by using toner serving as a developer. The toner image formed on the electrophotographic photosensitive drum is transferred onto a recording material such as a recording sheet or a plastic sheet. Heat and pressure are applied to the toner image transferred onto the recording material, whereby the toner image is fixed to the recording material for image recording.
Such an image forming apparatus typically needs replenishment of toner and maintenance of various process units. To facilitate the toner replenishment and the maintenance, a process cartridge in which an electrophotographic photosensitive drum, a charging unit, a developing unit, and a cleaning unit are integrated in a frame thereof and which can be detachably mounted on a main body of the image forming apparatus has been used.
Using such a process cartridge system, a user can perform maintenance of the image forming apparatus without any assistance. This can significantly improve operability, and an image forming apparatus having excellent usability can be provided. The process cartridge system is thus widely used in image forming apparatuses.
A main body of the electrophotographic image forming apparatus (hereinafter, also referred to simply as a “main body of the apparatus”) conventionally includes a main body-side engagement portion for transmitting rotational power to a rotating member, such as an electrophotographic photosensitive drum. Some apparatus main bodies are known to not include a mechanism for moving the main body-side engagement portion in the direction of a rotational axis of the rotating member according to an opening and closing operation of a main body cover of the main body of the apparatus.
A configuration related to a process cartridge that can be detached from the main body of the apparatus in a predetermined direction substantially orthogonal to the rotational axis of the rotating member has been known.
As for the foregoing configuration, there has also been known a configuration for bringing a coupling member arranged on the process cartridge into engagement with the main body-side engagement portion to transmit the rotational power.
Japanese Patent No. 4498407 discusses a coupling system serving as such a rotational force transmission unit, in which a coupling member arranged on an electrophotographic photosensitive drum unit is configured to be tiltable with respect to the rotational axis of the electrophotographic photosensitive drum unit. Such a configuration enables an engagement operation and a disengagement operation of the coupling unit according to mounting and dismounting operations of the process cartridge on/from the main body of the apparatus.